NOAA predicts near-normal Eastern Pacific hurricane season

May 24, 2012

NOAA’s Climate Prediction Center today announced that climate conditions point to a near-normal hurricane season in the Eastern Pacific this year. The outlook calls for a 50 percent probability of a near-normal season, a 30 percent probability of a below-normal season and a 20 percent probability of an above-normal season.

Seasonal hurricane forecasters estimate a 70 percent chance of 12 to 18 named storms, which includes 5 to 9 hurricanes, of which 2 to 5 are expected to become major hurricanes (Category 3, 4 or 5 on the Saffir-Simpson Hurricane Wind Scale).

An average Eastern Pacific hurricane season produces 15 named storms, with eight becoming hurricanes and four becoming major hurricanes. The Eastern Pacific hurricane season runs from May 15 through Nov. 30, with peak activity from July through September.

This outlook is based on the analysis and prediction of two competing climate signals:

Ongoing conditions, such as increased wind shear, that have been suppressing eastern Pacific hurricane seasons since 1995, and

The possible development of El Niño later in the season, with warmer waters in the eastern tropical Pacific Ocean, which can decrease the vertical wind shear and increase hurricane activity in the eastern Pacific region.

“The eastern Pacific has gotten off to a busy and early start of the season, with Tropical Storm Aletta last week and Hurricane Bud churning off the Mexican coast this week,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center, part of the U.S. National Weather Service. “NOAA’s seasonal hurricane outlook gives people an idea of how the season will likely unfold so they will be prepared and equipped to respond when disaster strikes. Despite our predictions, it only takes one hurricane to cause a lot of damage and loss of life if people aren’t prepared.”

The outlook is a general guide to the overall seasonal hurricane activity. It does not predict whether, where, or when any of these storms may hit land. Residents, businesses and government agencies of coastal and near-coastal regions should always prepare prior to each and every hurricane season regardless of the seasonal hurricane outlook.

Eastern Pacific tropical storms most often track westward over open waters, sometimes reaching Hawaii and beyond. However, some occasionally head toward the northeast and may bring rainfall to the arid southwestern United States during the summer months. Also, during any given season, two to three tropical storms can affect western Mexico or Central America.

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